Slave Drivers: Increased foraging by host workers under the slavemaking ant, Protomognathus americanus

In parasite-host interactions, the host is a part of the extended phenotype of the parasite and thus acts, often to its own detriment, in such a way that increases the parasite’s fitness. This study examines how the obligate slave-making parasite Protomognathus americanus alters the foraging of its Temnothorax spp. hosts. After comparing the foraging activity of 115 colonies with and without the parasite, parasitized colonies have a greater proportion of Temnothorax workers foraging for food, a shorter discovery time of food when it is available, and a greater proportion of total workers at a food source once it has been found. This novel behavioral manipulation may be explained in part by the greater depletion of fat reserves in the host worker force due to a disproportionate number of trophallactic exchanges between the parasite and the host, although further research is needed to determine the exact mechanism.